Background: In long QT syndrome (LQTS), beta blockers prevent arrhythmias. As a supplement, means to increase potassium has been suggested. We set to investigate the effect of moderate potassium elevation on cardiac repolarisation.
Methods: Patients with LQTS with a disease-causing or variant were included. In addition to usual beta-blocker treatment, patients were prescribed (1) 50 mg spironolactone () or (2) 100 mg spironolactone and 3 g potassium chloride per day (). Electrocardiographic measures were obtained at baseline and after 7 days of treatment.
Results: Twenty patients were enrolled (10 low dose and 10 high dose+). One patient was excluded due to severe influenza-like symptoms, and 5 of 19 patients completing the study had mild side effects. Plasma potassium in low dose did not increase in response to treatment (4.26±0.22 to 4.05±0.19 mmol/L, p=0.07). Also, no change was observed in resting QTcF (QT interval corrected using Fridericia's formula) before versus after treatment (478±7 vs 479±7 ms, p=0.9). In high dose+, potassium increased significantly from 4.08±0.29 to 4.48±0.54 mmol/L (p=0.001). However, no difference in QTcF was observed comparing before (472±8 ms) versus after (469±8 ms) (p=0.66) high dose treatment. No patients developed hyperkalaemia.
Conclusion: In patients with LQTS, high dose treatment increased plasma potassium by 0.4 mmol/L without cases of hyperkalaemia. However, the potassium increase did not shorten the QT interval and several patients had side effects. Considering the QT interval as a proxy for arrhythmic risk, our data do not support that potassium-elevating treatment has a role as antiarrhythmic prophylaxis in patients with LQTS with normal-range potassium levels.
Trial Registration Number: NCT03291145.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8449979 | PMC |
| http://dx.doi.org/10.1136/openhrt-2021-001670 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Calmodulinopathies are caused by mutations in calmodulin (CaM), and result in debilitating cardiac arrythmias such as long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT). In addition, many patients exhibit neurological comorbidities, including developmental delay and autism spectrum disorder. Until now, most work into these mutations has focused on cardiac effects, identifying impairment of Ca /CaM-dependent inactivation (CDI) of Ca 1.
View Article and Find Full Text PDFCongenital Long QT Syndrome Masquerading as Epilepsy: A Case Report.
Cureus
November 2024
Cardiology, Manchester University NHS Foundation Trust, Manchester, GBR.
In this case report, we present a 24-year-old woman with a previous diagnosis of epilepsy who was admitted to the hospital following loss of consciousness (LOC). It was initially assumed that this was an epileptic seizure based on her previous diagnosis of epilepsy; however, a review of her electrocardiograms (ECGs) revealed a prolonged QT interval. She was admitted to the cardiology ward for continuous ECG monitoring and subsequently developed self-limiting torsades de pointes (TDP).
View Article and Find Full Text PDFNovel risk predictor of arrhythmias for patients with potassium channel related congenital Long-QT Syndrome.
Heart Rhythm
December 2024
Department of Experimental Cardiology, Heart Centre, Amsterdam University Medical Centres, University of Amsterdam, Amsterdam, the Netherlands; Member of the European Reference Network for rare, low prevalence and complex diseases of the heart: ERN GUARD-Heart. Electronic address:
Background: Congenital long-QT syndrome (LQTS) is characterized by delayed ventricular repolarization, predisposing to potentially lethal ventricular arrhythmias. The variability in disease severity among patients remains largely unexplored, underscoring the limitations of current risk stratification methods.
Objective: We aimed to evaluate the potential utility of exercise stress test (EST) electrocardiographic markers in identifying high-risk LQTS patients.
The Yield of Genetic Testing and Putative Genetic Factors of Disease Heterogeneity in Long QT Syndrome Patients.
Int J Mol Sci
November 2024
National Medical Research Center for Therapy and Preventive Medicine, 101990 Moscow, Russia.
Article Synopsis
- * Among 82 LQTS patients, a 75% diagnostic yield was found in those with high Schwartz scores, while 50% of those with lower scores (<3.5) were diagnosed through broader genetic testing.
- * The findings suggest that the existing LQTS genetic diagnosis framework may not effectively capture cases with lower Schwartz scores, and additional rare variants could indicate more severe disease, pointing towards the need for improved referral criteria.
Coronary artery disease and the risk of life-threatening cardiac events after age 40 in long QT syndrome.
Front Cardiovasc Med
October 2024
Department of Cardiology, Rabin Medical Center, Petah-Tikva and the Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Background And Aims: Long QT syndrome (LQTS) and coronary artery disease (CAD) are both associated with increased risk of ventricular tachyarrhythmia However, there are limited data on the incremental risk conferred by CAD in adult patients with congenital LQTS. We aimed to investigate the risk associated with CAD and life threatening events (LTEs) in patients with LQTS after age 40 years.
Methods: The risk of LTEs (comprising aborted cardiac arrest, sudden cardiac death, or appropriate defibrillator shock) from age 40 through 75 years was examined in 1,020 subjects from the Rochester LQTS registry, categorized to CAD ( = 137) or no-CAD ( = 883) subgroups.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!